Mark Treleaven

Last week I replaced the ignition actuator because of a no start/no crank.

We haven't driven the Jeep much since, but tonight my wife pulled into the driveway and turn the ignition off but the Jeep kept running. She tried multiple times to turn it off and even took out the key but it still ran.

By the time I got outside to see what was going on, the engine bay was making a horrible mechanical sound. I reached in and turned the key and it turned off right away. There was a burning smell coming from the engine bay that smelt like burnt clutch.

After that, it did not start up again.

Being familiar with no start issues from last week, I checked all the fuses and relays. Everything is good.

I also turned the key to the on position and tried jumping the solenoid on the starter. There was a tiny little spark but it did nothing at all.

I got underneath and tried to tap the starter while she cranked it over but nothing happened.

I can hear the starter click loudly when she was cranking it over.

Any ideas. My guess is the starter is bad, but the smell and horrible noise while it was running have me thinking it could be something else.

PatHenry

If I remember correctly, the engine was "dieseling".. something I've only read about myself.

You should definitely pull the starter and take it down to the parts store and have them bench test it. Clicking is a classic "bad solenoid" symptom. If it's bad you need a new one and if not then you've eliminated that.

I'd guess (wildly I might add) that the ignition switch may be bad. What year is it?

Mark Treleaven

It is a 98 4.0 with Auto.

PatHenry

I'm sure there's info to test the ignition switch with a multi-meter. It's actually pretty easy to R/R.. the hardest part is you need to have a security torx bit (like a regular one but it has a hole in the center in case theives are unaware you can buy the security bits at any decent parts/tool store.
But I'd start by removing the starter and bench testing. Autozone will do this for free for you (as will most other parts stores).

When myy ignition switch went on my 00 TJ it was due to it being worn out, the thing is just some plastic and springs... very cheap feel to it, even the OEM... but my problem was the opposite, it would take 20 tries to get the key to engage with lots of wiggling. I suppose that the opposite (not disengaging) is possible.

Mark Treleaven

I tested the starter. Getting power to the top post on the starter but when I arc it to either of the other posts, it either clicks or does nothing at all.

The starter looks to be the original, and is caked in mud. We have also had starter issues(it grinding now and then) since we bought the Jeep so maybe a new starter will be the cure.

PatHenry

It smacks of failing/failed solenoid, but I've never heard of such a dramatic and spectacular failure when the engine was already running.

I still can't wrap my head around the other behavior. I'm hoping someone smarter than I (not a high bar by any means) can advise.

Mark Treleaven

I tested pin 86 on the starter relay too and it was getting 12V. That would rule out the starter solenoid correct?

PatHenry

I feel like you might have seized the starter, and since the solenoid is integrated in the unit, you're replacing it regardless.

I would not discount a problem with the ignition switch. Fuel injected engines shouldn't be able to "diesel" in the classic sense since the fuel and ignition are electric... yet you had "dieseling" type run-on. Logically that means the power was NOT cut when the key was moved to off.. so the switch didn't cut the circuit but did allow the key to move.

Now who knows, on my 00TJ I could pull the key out of the ignition at free random, that was due to the worn lock cylinder and not operation of the engine when the ignition was in the off position.
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Is it possible the horrid mechanical sound was the starter engaging? Or maybe the starter running full bore and keeping the engine going?

jordan96xj

This all leads back to faulty or incorrect ignition switch operation. It never turned the vehicle off (it didn't open the circuits), and the sound was most likely the starter being engaged.

PatHenry

That is exactly what I was thinking as well.

Replacing the switch is really a lot easier than you might expect. There are a lot of youtube videos available for reference and the switch is $40 for a cheap Autozone one (though they do have a lifetime warranty.)

Mark Treleaven

Up here in Canada the cheapest one is $80. I just had it apart last week while changing the ignition actuator so it's not to hard at all.

I also grabbed a used starter so I can check to make sure my starter is toast fairly easily.

Mark Treleaven

So, I replaced the starter, and the ignition actuator. It cranks now but there is no starting.

PatHenry

Is it the used starter? Also do you mean ignition switch or are you referring to the actuator you'd done a week back?

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Mark Treleaven

It was a new starter, and the ignition switch itself. I checked and I am not getting any spark. I checked the CPS and it checked good. All fuses are good, relays are all good.

PatHenry

I'm trying to imagine how a starter blowing up could lead to a no spark condition..
I wonder if a chain reaction (no pun intended) was set off that caused the engine to jump time or something. Seems far-fetched..

I wonder if you fried the computer.